Search engine giants rule the online advertising market. It's no surprise to find that the most popular search engine here -- Google (NASDAQ:GOOG) -- is also the top dog in Web-based marketing. The same goes in China, where (NASDAQ:BIDU) rules on both fronts.

Baidu has competition in the world's most populous nation. Google is a distant second, though other Internet specialists like SINA (NASDAQ:SINA) and Focus Media's (NASDAQ:FMCN) Allyes are material players in whipping up interactive sponsorships.

Now we can toss Alibaba Group into the mix. The parent company of the recently public B2B site, as well as China's leading consumer auction marketplace website in Taobao, is officially launching Alimama this morning.

Alimama is an advertising network, not all that different from Baidu Union or Google AdSense. Alimama claims that it will dig deeper to appeal to the smallest of websites and blogs that aren't represented by Baidu or Google, though Google's never been one to turn down a promising partner based on size. AdSense even allows seamless integration of its targeted ads to users.

So where will Alimama fit? Well, it's lived up to its enabler promise. Since its beta launch three months ago, the network has signed up 150,000 publishers and another 135,000 personal blogs. That's enough traffic to deliver a billion daily page views.

It makes you wonder why Google and Baidu let all this traffic go unmonetized for so long. It also leads one to think that Yahoo! (NASDAQ:YHOO) may be back. Alimama is selling its own ads, but Yahoo! owns a 39% stake in Alibaba Group.

"No longer will 80% of China's website traffic go unmonetized," Alibaba Group spokesperson Jin Jianhang is quoted as saying in this morning's press release.

If true, it won't be long before Google and Baidu come diving in for a piece of that. Instead of viewing Alimama as a threat, they should see it as a miner, taking a pickaxe to a market that's substantially wider than anyone thought possible.

In other words, it's good news for Alimama today, but it may very well be good news for everyone else tomorrow.

For more Foolish company: